Promise
by Moxietek
Summary: A familiar villian severely injures Genos, forcing Saitama to deal with the aftermath.


_Originally from my Ask Blog on Tumblr:_ **ask-demon-cyborg**

* * *

"Well, well, well. Look at what the cat dragged in."

The husky voice vibrated off the crumbling walls that made up the former nuclear power plant. Nearby citizens and animals had long left since the leakage of radiation, causing a heavy silence to permanently blanket the area.

Standing confidently at the far end of the building, was a mirror counterpart of the B-Class hero who had just wandered into the room. Every aspect of him was perfectly replicated, aside from the different coloured suit and spine-chilling crimson hues. Oh. Also, a dark mop of carelessly groomed locks was situated on top of his head.

"…It's not fair."

The man opposite of him smiled mockingly.

"What's not fair?"

"You still have hair and strength."

He choked out a chuckle.

"Is that all you care about? Is my hair more important than that hunk of metal I borrowed from you?"

"Of course not."

Saitama glanced around him.

"Where's Genos?"

The villain's grin split his face in half.

"You tell me."

"Huh?"

"I don't know where blondie could be. He could be in a trash compacter, just awaiting his own demise."

Saitama stamped his foot into the ground, creating a number of cracks that ran across the concrete.

"Don't talk shit! You know exactly where Genos is!"

Another laugh rung out from the man's lips.

"Woah, now. No need to have a temper tantrum. Your so-called 'disciple' is fine. He may be a little more…compact than you remember."

"What did you do to him…?"

"Nothing exciting. We just played a few games."

Nonchalantly idling over to the shadow infested corner, he reached forward, retrieving something that had been intentionally hidden.

"But if you really want to see him, here he is. Well, what's left of him."

Within the man's grasp was an all-too-familiar core, which once radiated a vibrant aqua. However, at this moment and time, a weak glow was all that emitted from the spherical structure. Hanging from the connected thick cord was Genos. Or simply, his torso and head.

All four limbs had been ripped off, indicated by the sparking wires that splayed out of the empty sockets.

Chunks of his blonde locks had been torn off his armour plated scalp. In addition, the surface itself was sporting a large hole in the side of the cyborg's head, revealing the human organ inside. Cerebrospinal fluid trickled down his face, seeping into the fractured gaps in his cheek.

A gloomy yellow eye stared at Saitama, the other one having been dislodged by impatient fingers.

" _Sen…sei._ " Genos mouthed, unable to re-activate his vocal software once the hardware was crushed into a crumpled cube.

"I don't get why you like him so much. After all, he's nothing but a kid in a glorified robot body."

"…"

"Nothing to say, eh? I suppose I'll just switch him off then. Say goodbye to this shitty excuse of a hero."

"Oi."

"Oh, also, remind me never to shave my hair. I look horrible with a bald head."

Not even a second after the man had ceased his teasing, a gloved palm was on his neck, constricting around his windpipe.

" **You just crossed the line, asshole.** "

...

Boulders coursed through the dust-ridden air, all lifted and thrown aside by the one man who was so desperately searching for something. Someone.

Now that the instigator of the situation had been smashed into a nearby crater and buried under an avalanche of rubble and dying vegetation, he was free to hunt down the remains of his disciple.

He just dearly prayed to the gods, which he did not even believe in, that the boy's literal "life line" had not been severed in the midst of his battle with the devil. After all, he had promised to tutor Genos till he was strong enough to reach his desired goal and obtain sweet revenge.

Saitama did not like breaking promises.

Upturning a flat slab of shattered concrete, he spotted him.

And he almost wished he didn't.

The greater part of the cyborg's artificial skin was missing, exposing the inner titanium frame. Even then, the metallic material was sporting countless scratches and miniature cracks noticeably weakened it's durability.

Previously shiny plates of his armour were scuffed and dented, dirt clogging up the gaps situated between them. Wires no longer sparked, and instead, they lay limply against the rough surface.

Remnants of his fluffy blonde locks were caked with grime and small pebbles. Filth dusted over the pale tissue of the only human organ residing within Genos.

It was uneasy. Seeing his energetic disciple motionless upon the ground.

Additionally, the lack of familiar gold gleaming from his remaining black sclera was disturbing.

"Hey. I did it, Genos. I got that bastard back for what he did to you."

No response.

"…You there, Genos?"

Brushing the tip of his fingertip over the last sections of skin, he noticed the dark-shaded streaks trailing down from the other's eye sockets.

Had he been crying?

"Oi."

Following the structure of the visibly damaged, yet still intact chrome cord, Saitama reached out and carefully scooped up the flickering core with the gentleness of a mother.

He was basically holding the boy's heart.

Turquoise flickered from within the centre of the sphere, the glow becoming increasingly dimmer and dimmer. A thought popped into his head as the colour faded out of existence for a moment before flaring up in a gloomier shade than it had initially been.

 _Genos is dying._

 **...**

Saitama had never ran so fast in his life.

If some person had timed the amount of minutes it had taken him to dash straight to Dr Kuseno's lab, he was sure that it would be a world record. Perhaps the quickest in the universe.

But breaking the speed of sound was the least of his worries right now.

Sat upon the chair that had been provided for him, he dug the points of his elbows into his thighs in order to prop his head up on his flattened palms.

He wasn't sure how long he had been sitting in solitary for.

The limited words he had exchanged with the Doctor continued to replay themselves in his mind.

 _"Can you fix him?!"_

 _"I'll try my best."_

 _"Is that a yes?"_

 _"…"_

 **...**

"Saitama."

The mere mention of his name should not have scared the living daylights out of a twenty five year old man, but it did.

Maybe that was one of the side effects of silently drowning in his own anguish for over three days.

He looked over at the scientist, wincing at the stiff ache of neglected muscles.

"Y-Yeah?"

His voice cracked.

"Please return to your apartment. Genos' repairs may not be fully complete for another few days and I do not want you starving yourself out here."

Dr Kuseno gradually stepped out of the room that he had been working in for the last dozens of hours.

"…Why is it taking so long? Don't you just need to clean his body then reattach his arms and legs?" Saitama responded hesitantly, slouching back in the seat for the first time in hours.

"It isn't as simple as that, my boy. I shall not bore you with the exact details since Genos once told me that you did not enjoy lengthy discussions."

His stomach coiled at the kind smile that masked the other's fatigue.

"Simply, the very energy of his core has been depleted massively. While I am working on restoring the lost power, an entire body has to be created for him as his current one has been destroyed in too many sections. Also, there has been mild damage done to his brain."

"…Oh."

"Yes…So, I advise that you return to your home and rest. You've been staying up for the last couple of nights, right?"

"Yeah…"

"You need to sleep and eat, Saitama. No matter how strong you are."

"…I think I'll stay here. I'll be fine."

"Saitama, I really-"

"Sorry, Doc, but I'm not going back unless Genos comes with me as well."

Dr Kuseno let out a sigh.

"…If you insist, but please remember that if you ever feel like having a meal, just knock and I'll make you something."

"Thanks."

And with that final praise, the elder man receded back into the adjacent room, automatic doors sliding shut to separate them.

Now that he was alone, Saitama clenched his trembling hand up into a signature crimson fist, glaring at it with glassy hazel eyes.

 _What's good about being the strongest man in the world if you can't even save the one closest to you?_

 **...**

Days converted into weeks.

But he did not once leave the establishment. He barely moved from his chair outside the operation room.

Due to Dr Kuseno's insistence, he took daily showers, ate the occasional lunch, preformed petty exercises and generally took care of himself. Although, not a single trace of emotion ever graced the male's lips.

Everything single thing he did was done with haste and carelessness, as if he was expecting something to happen while he was away from his permanent seat.

And it did not take a genius to figure out that Saitama was anxiously waiting for Genos to be up on his feet once more.

"Hey, Doc."

Saitama spoke up during one of the many dinners that he shared with the scientist.

Pleasantly surprised by the other's attempt at starting a conversation, Dr Kuseno smiled at him.

"Yes?"

"Did Genos talk about me when he came here to get fixed up?"

"Oh, yes, he did. He's extremely fond of you, Saitama. I remember one particular occasion when he returned for a minor upgrade. I think this was a couple of months after he met you. He was the happiest I've ever seen him. He ranted on and on about how he thoroughly enjoyed washing dishes and grocery shopping. It was rather odd, if I must say, but I was so glad for him. He seemed to smile the entire time when-Saitama?"

A clear bead of liquid rolled down the hero's cheek.

 **...**

It's been a month since he was last referred to as "Sensei".

He would never admit it, but he terribly missed the title.

Saitama's days were awfully boring. He'd wake up from an unrestful slumber and start his morning stretches, no matter what time of day it was. Then, he'd eat something with the Doctor. After that, he returned to sitting down till he deemed it was time to wash. Finally, he would wait until sleep consumed his mind.

It was painfully dull.

Just like his life before he met Genos.

 **...**

One day, Dr Kuseno came out the secluded area and smiled at him. But it wasn't one of compassion.

"Saitama, I have some news for you."

The man was listening from the moment he pronounced the first syllable of his name.

"Yes?"

"I have developed a new core for Genos, since his previous was no longer able to harness the sufficient energy needed for future combat after he was severely impaired."

"That's…That's great!"

"But there is a 86% chance that the software included with it, might overwrite his existing memories and personal files stored on his system."

"…What does that mean?"

"It means there is a chance that Genos may not recognise you when he sees you, Saitama."

 **...**

Anxiety had been something he had successfully subdued ever since he began training. So, why was his heart thumping at deafening decibels?

It wasn't like he was about to throw a concert for every single person in the world.

He was merely standing in-front of a door.

But the idea of being forgotten by the boy that changed his life was overwhelming.

Saitama never excelled at mathematics when he was in school, but he definitely knew that 86% was really high.

What would he do if Genos did not remember him?

He had no time to elaborate on that question as the wall parted into an opening and Dr Kuseno strolled out. With a blonde cyborg attached to his hand.

The breath left his very lungs as eyes roamed over the other's newly forged figure.

Genos' arms were finished with silver and white plates, perfectly sculpted to form athletic-looking biceps. He was dressed in a cream hoodie with it's sleeves torn off to accommodate his style and purpose. Black jeans hugged his long legs, which were most likely as flawless as the rest of him.

Blonde locks appeared as if they had been styled by a professional, the strands falling in places that accentuated his features. Synthetic skin covered the entirety of his face once more,

His eyes were shut, shielding those stunning golden eyes from view.

Saitama was overjoyed and…heartbroken?

Dr Kuseno watched the man for the signal, and when he received it, a hopeful grin made it's way onto his face.

"Son, you can look now."

Genos' LEDs were activated, bringing the dark pools to life as his eyelids slid open.

 _Please._

Seconds past before one of the three men reacted.

 _Please._

"…Sensei?"

 _Thank you._

Stumbling forward into the cyborg's chest, Saitama tugged him into an tight embrace.

"Genos…"

"…What is it, Sensei?"

The strongest man in the world shook as sobs wrecked his composure.

"…Don't ever leave me again."

Oil spilled down Genos' face.

"I-I'm so sorry. I will never do that, Sensei…"

" **…Promise?** "

" **Promise**."


End file.
